1. Field of the Invention
The present invention relates to the use of a novel retinoid, particularly a retinol derivative. More particularly, the present invention relates to the use of topical compositions having the retinol derivative, retinoxytrimethylsilane, to treat, including prevent, ameliorate and/or reduce, signs of dermatological aging, especially wrinkles, and/or improve the aesthetic appearance of skin. Still more particularly, the present invention provides the beneficial effects of retinol without causing skin irritation from daily use.
2. Description of the Prior Art
Retinoid or retinoid compounds/derivatives (collectively referred to herein as xe2x80x9cretinoidxe2x80x9d or xe2x80x9cretinoidsxe2x80x9d) are vitamin A derivatives. They are used in topical compositions to treat a variety of adverse skin conditions. Such skin conditions include acne, actinic damage, dandruff, eczema, fine lines, psoriasis, warts and wrinkles.
Retinoids used in the prior art include, but are not limited to, isotretinoin, retinal, retinol, retinoic acid, retinyl acetate, retinyl palmitate, retinyl propionate, synthetic retinoid mimics, and tretinoin. As is known in the art, the amount of retinoid in a topical composition varies depending on the condition to be treated, as well as on the composition and the retinoids themselves. Representative compositions having a retinoid are discussed, by way of example, in U.S. Pat. Nos. 3,006,939; 3,060,229; 3,932,665; 4,826,828; and 4,934,114.
However, topical compositions having a retinoid have been limited in the amount of retinoid, since retinoid has been found to irritate the skin. Such irritation is acute, especially when the amount of retinoid in the composition is high. However, some consumers with sensitive skin cannot even tolerate a small amount of retinoid.
The irritation can manifest itself in the form of physical discomfort and/or unaesthetic skin appearance. Such an unaesthetic skin appearance can manifest itself by dermatitis or erythema. The irritation may disturb the user to such an extent that the user will discontinue use of the composition having a retinoid. Alternately, the user may reduce the frequency of use, thereby possibly reducing the effectiveness of the composition for its intended purpose.
Heretofore, there has not been an efficacious skin care composition that contains a retinoid, but without the irritation induced by a retinoid. Historically, it has been observed that retinoid-induced skin irritation has a direct correlation to retinoid efficacy. Namely, the greater the concentration of retinol, the more likely that irritation will occur. Thus, simply reducing the retinoid concentration might decrease irritation to the skin, but it would also reduce the desired retinoid efficacy. Consumers require, and would benefit from, a retinol-delivering composition that is both well-tolerated and efficacious. The present composition having the retinoid, retinoxytrimethylsilane, achieves this need.
It is an object of the present invention to provide a topical composition having retinoxytrimethylsilane to treat, including prevent, ameliorate and/or reduce, signs of dermatological aging, especially wrinkles, and/or improve the aesthetic appearance of skin, and methods of its use.
It is another object to provide such a topical composition that is substantially anhydrous.
It is a further object of the present invention to provide a method for delivering the benefits of retinol without inducing irritation.
These and other objects and advantages of the present invention are achieved by a topical composition that has retinoxytrimethylsilane in an effective amount, preferably about 0.1 weight percent (wt %) to about 50 wt % of the total weight of the composition.
The present invention relates to the surprising recognition that retinoxytrimethylsilane, a retinol derivative, delivers retinoid efficacy without skin irritation, dryness or erythema typically caused by the topical use of a retinoid. Further, it has also been discovered in the present invention that moisture-activated, retinol-delivering compositions having retinoxytrimethylsilane will treat, including prevent, ameliorate, and/or reduce, signs of dermatological aging, especially wrinkling and/or improve the aesthetic appearance of the skin upon daily application to skin. The composition is preferably applied topically once or twice daily. The daily application can be for periods up to two weeks, four weeks or more.
The present compositions preferably have an amount of retinoxytrimethylsilane from about 0.1 wt % to about 50 wt %, based on the total weight of the composition. More preferably, the present compositions have retinoxytrimethylsilane in an amount from about 0.5 wt % to about 15 wt %. Most preferably, the present compositions have retinoxytrimethylsilane in an amount from about 0.5 wt % to about 5 wt % of the total composition. To provide guidance to those skilled in the art for practicing the present invention, the efficacy of the retinol-derivative concentration in a topical composition is approximately equivalent to 10xe2x88x921 concentration of retinol percent by weight of the composition. For example, to provide the efficacy of about 0.1 wt % (based upon the total weight of the composition) retinol activity, a composition of the present invention preferably includes about 1 wt % of retinoxytrimethylsilane.
In addition to improvements in skin care benefits of the present invention, the retinol-derivative, retinoxytrimethylsilane, results in more stable compositions than those of the prior art. This is evidenced by a lasting white color of the present compositions, without the manifestation of yellowing over time, particularly in a stick product form. The present compositions can also be in other cosmetic product forms, such as, for example, an emulsion, a gel, a lip balm, a lip gloss, a lotion, a mask, an ointment, a patch, a pomade, a solution, a spray, or a towelete.
The present compositions are preferably wax-based, oil-based, or silicone-based compositions, all of which are substantially anhydrous (i.e., contain less than about 1 wt %, more preferably no, water). Alternatively, the compositions may include greater than 1 wt % water as long as contact between the retinoxytrimethylsilane and water is prevented. For example, a two-phase product that is dispensed in a dual-chamber package with each phase in a separate chamber may include an aqueous phase in one chamber and the retinoxytrimethylsilane in substantially anhydrous phase in the other chamber. As the contents from each chamber are dispensed, the phases may combine either via the dispensing mechanism, as is known in the art, or mixed by the user as the user rubs the two phases onto and into the skin.
In a preferred embodiment of the present invention, the retinoxytrimethylsilane used is in soybean oil and is commercially available from Clariant Corp. under the tradename SilCare 1 M 75. The Clariant product is a 12% chemically reactive liquid derivative of retinol, which is readily dispersible in most substantially anhydrous organic cosmetic formulations at room temperature.
The compositions of the present invention yield improvements to the aesthetic appearance of the skin by treating, including preventing, ameliorating and/or reducing at least one of the following: dermatological aging, especially chronological, actinic or hormonal aging, skin fragility, loss of collagen and/or elastin, skin atrophy, skin dryness, skin flakiness, skin discoloration, skin sagging, signs of skin fatigue and/or stress, acne, psoriasis, eczema, and warts. In particular, improvements to the aesthetic appearance of skin include at least one of the following: makes facial lines appear less noticeable, makes facial lines and/or wrinkles feel plumped, improves appearance of suborbital lines and/or periorbital lines, improves appearance of crow""s feet, reduces and/or diminishes the appearance of wrinkles, particularly facial wrinkles on the cheeks, forehead and/or around the mouth, and particularly deep wrinkles, rejuvenates and/or revitalizes skin, particularly aging skin, improves skin firmness and/or plumpness, improves skin tone, enhances skin thickness, decreases pore size, improves skin moisture and/or hydration, improves skin texture, reduces and/or eliminates fine and/or deep lines, smoothes skin, restores skin luster and/or brightness, and improves skin resiliency, flexibility and/or elasticity.
A preferred embodiment of the topical compositions of the present invention also includes at least one of the following: a surface smoother, a skin plumper, an optical diffuser, a sunscreen, an exfoliation promoter, and an antioxidant.
A surface smoother provides the functional benefits of enhancing skin smoothness and reducing the appearance of fine lines and coarse wrinkles. Examples include silicas, talcs, isopropyl myristate, petrolatum, isopropyl lanolate, silicones (e.g., methicone, dimethicone), polymethylmethacrylate (PMMA), or any mixtures thereof. The surface smoother is preferably present from about 0.1 wt % to about 50 wt % of the total weight of the composition.
A skin plumper serves as a collagen enhancer to the skin. An example of a suitable, and preferred, skin plumper is palmitoyl oligopeptide. Other skin plumpers are collagen and/or glycosaminoglycan (GAG) enhancing agents. The skin plumper is preferably present from about 0.1 wt % to about 20 wt % of the total weight of the composition.
An optical diffuser is a particle that changes the surface optometrics of skin, resulting in a visual blurring and softening of, for example, lines and wrinkles. Examples of optical diffusers that can be used in the present invention include, but are not limited to, boron nitride, mica, nylon, polyurethane powder, sericite, silica, silicone powder, talc, Teflon, titanium dioxide, zinc oxide, or any mixtures thereof. The optical diffuser is preferably present from about 0.01 wt % to about 20 wt % of the total weight of the composition.
A sunscreen protects the skin from damaging ultraviolet rays. In an illustrative embodiment of the present invention, the sunscreen would provide both UVA and UVB protection, by using either a single sunscreen or a combination of sunscreens. Among the sunscreens that can be employed in the present compositions are avobenzone, cinnamic acid derivatives (such as octylmethoxy cinnamate), octyl salicylate, oxybenzone, titanium dioxide, zinc oxide, or any mixtures thereof. Preferably, the sunscreen is present from about 1 wt % to about 30 wt % of the total weight of the composition. In particular, the addition of a sunscreen is preferred to prevent/reduce the photodegradation of retinoid while in the package and/or on the skin.
The compositions of the present invention having sunscreen bring about additional improvements to the aesthetic appearance of skin, including at least one of the following: minimizes sunburning, minimizes tanning, and reduces redness.
The present compositions may also have one or more exfoliation promoters. Suitable examples of an exfoliation promoter that can be used in the present compositions include alpha hydroxy acids; benzoyl peroxide; beta hydroxy acids; keto acids, such as pyruvic acid, 2-oxopropanoic acid, 2-oxobutanoic acid, and 2-oxopentanoic acid; oxa acids as disclosed in U.S. Pat. Nos. 5,847,003 and 5,834,513 (the disclosures of which are incorporated herein by reference); salicylic acid; stearoxytrimethylsilane (available from Clariant under the tradename SILCARE 1 M 71); trimethylsilyl trimethylsiloxy glycolate (available from Clariant under the trade name SILCARE 180 M 30); trimethylsilyl trimethylsiloxy lactate (available from Clariant under the tradename SILCARE 180 M 10); urea; or any mixtures thereof. The preferred exfoliation promoters are 3,6,9-trioxaundecanedioic acid, glycolic acid, lactic acid, or any mixtures thereof.
When the present invention includes an exfoliation promoter, the composition has about 1 wt % to 20 wt %, preferably about 1 wt % to about 15 wt %, more preferably about 4 wt % to about 10 wt %, and most preferably about 4 wt %, of the exfoliation promoter based on the total weight of the composition.
An antioxidant functions, among other things, to scavenge free radicals from skin to protect the skin from environmental agressors. Examples of antioxidants that may be used in the present compositions include compounds having phenolic hydroxy functions, such as ascorbic acid and its derivatives/esters; beta-carotene; catechins; curcumin; ferulic acid derivatives (e.g. ethyl ferulate, sodium ferulate); gallic acid derivatives (e.g. propyl gallate); lycopene; reductic acid; rosmarinic acid; tannic acid; tetrahydrocurcumin; tocopherol and its derivatives; uric acid; or any mixtures thereof. Other suitable antioxidants are those that have one or more thiol functions (xe2x80x94SH), in either reduced or non-reduced form, such as glutathione, lipoic acid, thioglycolic acid, and other sulfhydryl compounds. The antioxidant may be inorganic, such as bisulfites, metabisulfites, sulfites, or other inorganic salts and acids containing sulfur. Compositions of the present invention may have an antioxidant preferably from about 0.001 wt % to about 10 wt %, and more preferably from about 0.001 wt % to about 5 wt %, of the total weight of the composition.
The present composition may also have one or more of the following ingredients or adjuvants: anesthetics, anti-allergenics, antifungals, antiseptics, chelating agents, colorants, demulcents, emollients, emulsifiers, fragrances, humectants, lubricants, moisturizers, pH adjusters, pigment altering agents, preservatives, skin penetration enhancers, stabilizers, surfactants, thickeners, viscosity modifiers, vitamins, or any mixtures thereof.
The component(s) of the present invention are preferably contained in a cosmetically acceptable vehicle. Suitable vehicles of the present invention may also include mineral oil, petrolatum, polydecene, and vegetable oil.
To form the exemplary wax-based stick products of the present invention, processing is undertaken at typical temperatures for that type of base (e.g., about 150xc2x0 F. to about 170xc2x0 F.), over extended periods of time. Higher temperatures are feasible due to greater stability of the retinol-derivative of the current invention as compared to active retinol. Also, processing at room temperature is a suitable means for forming the compositions of the present invention. In short, the present compositions can be processed from room temperature just up to about 180xc2x0 F., even though about 150xc2x0 F. to about 170xc2x0 F. is preferred.
The following is an illustrative, non-limiting example of a composition of the present invention.